1. Field of the Invention
The invention relates to a process for the addition of ferrocene to combustion or motor fuels in order to improve their combustion with atmospheric oxygen or oxygen-containing gases.
2. Description of the Related Art
To reduce the consumption of combustion or motor fuels, to decrease emissions during the combustion of combustion or motor fuels and to remove or reduce the carbon deposits when motor vehicle engines are running, liquid hydrocarbon mixtures, comprising in essence gasoline and an organometallic compound from the group of [bis(.eta.-cyclopentadienyl)-iron], called ferrocene in the following, and gasoline-soluble derivatives of ferrocene have been proposed (see DE-OS 25 02 307).
Furthermore, for the purpose of reducing the consumption of motor fuel and the exhaust emission in an Otto engine equipped with an exhaust gas catalyst system for exhaust gas afterburning, the use of a liquid motor fuel with an addition of 1 to 100 ppm by wt. of ferrocene has been proposed (see DE 38 01 947 A1).
For the purpose of avoiding unreliably high exhaust gas back pressure when running a diesel engine equipped with a particulate filter in the exhaust stream, the use of a motor lubricant, to which a catalytically effective content, amounting to 5 to 20,000 ppm, of an iron compound is added, has been proposed. Among others, ferrocene was taken into consideration as the iron compound (see DE 38 09 307 A1).
In an earlier German patent application P 41 29 408, a device and a process for the direct addition of a solid additive--ferrocene--to liquid motor fuels have been proposed, where, controlled by means of pulverizing ferrocene compacts, ferrocene is added to the liquid fuel in metered amounts.
All of these methods have in common that here an addition to the liquid fuel or even combustion fuel, e.g., heating oil, was effected, utilizing the solubility properties of the added additive, here ferrocene or ferrocene derivatives. The same also applies to the addition to the motor lubricant, which can take place by directly dissolving or also by preparing concentrated solvents in solvents compatible with the motor lubricant and by their addition to the lubricant.
The preparation of suitable solutions or stock solutions is inconvenient and expensive on account of the required metering and mixing apparatuses and the related operations. In addition, additional measures are required in order to ensure the stability and the specified properties of the motor or combustion fuels to which ferrocene or ferrocene derivatives are added. This kind of metering has also the drawback that the addition of the additive can be optimized only for a specific operating point.